I've used LensRentals and I absolutely loved their service. You reserve a camera/lens/accessories for a specific date, they ship it out to you via 2-Day FedEx on or even a day or so before that date, you used it for the rental period, you ship it back in the same box (they provide a return label) on the last date of the rental period. All the lens comes in a case of some sort, even the cameras come with a shoulder bag to carry them. Simple enough =)
I can't help, but I'm just posting to let you know that a member was a bit wary of camerent.co.uk the other day on this board. He went to the office address listed on the site, and the owners had never heard of them. YMMV. I don't want to unfairly criticise them or anything - just passing on the info Edit: errr... only if you're from the UK obviously, lol. My bad.
Where are you? Near me (So. California) there are a few places where I can walk in and rent a lens. The deals are better than the on-line places and there is no shipping. You might look around locally
I've had great experience with Borrow Lenses. They are based in the Bay Area, but will ship all over the US. http://borrowlenses.com/
Camerent Regarding Camerent (http://www.camerent.co.uk/), I would have to recommend you steer well clear of them. I hired a Canon 1d Mark III from them and stupidly forgot to return the Sandisk compact flash card that came with it. I have since had nothing but hassle trying to deliver both the original card and a replacement card I then purchased, back to them. Their Mayfair office doesn't accept postal deliveries, even if sent via Special Delivery, despite what their customer services team tell you. I'm still waiting for the return of my deposit, over a month after I hired the camera !. They even chose to charge me for the for the period of time when the camera could not have been hired out, due to it missing the card, meaning I will only get £895 of my deposit back. In my opinion, very poor customer service.
I recently used http://www.lensprotogo.com Their prices include 3 day shipping to you and return shipping. I checked out LensRentals and it was $65 for a 50mm lens and $25 to ship and at LensProToGo it was $65 with shipping and insurance included. Just throwing it out there =)
I've rented from LensRentals numerous times, great bunch of people to work with. http://www.lensrentals.com/
I second the http://www.borrowlenses.com recommendation. If you join their facebook page, they run occasional specials too which are great.
LensRentals. No one else come close. There's no reason to use anyone but them. They are 10/10, A+, etc. BorrowLenses does not have the same sterling reputation.